Field of the Invention
The present disclosure relates to an apparatus for controlling an Inverse Fast Fourier Transform input in a Long Term Evolution system, and more particularly, to a technology for reducing a memory size, a latency, and an addition/subtraction operation of a butterfly in a first stage of Inverse Fast Fourier Transform.
Description of the Related Art
Since Orthogonal Frequency Division Multiplexing (OFDM) which is one of multi-carrier transmission methods has a robust performance in an environment such as a multipath fading channel, it is widely used in various wireless communication technologies. The OFDM is adopted as a standard of a Long Term Evolution (LTE) system of a 3rd Generation Partnership Project (3GPP).
A Fast Fourier Transform (FFT) processor is one of important factors in an aspect of physical layer implementation in various wireless communication systems as it requires a large area and power consumption. Meanwhile, various studies for improving the performance of Fast Fourier Transform have been progressed. However, most studies have focused on the problem of reducing the complexity of a multiplier.